Plate clamp



Oct' 17, 1944' Y R. s. 4WALDRUP 2,360,602

PLATE CLAMP Filed Feb. 19, 1944 Patented Oct. 17, 1944 UNITED STATESPATENT OFFICE PLATE CLAMP Rodney rSv. Waldrup, Houston, Tex. lApplication February 19, 1944, serial No. 523,714.7

. Claims'.

rThis invention relates to a clamp and has particular relation to thattype of clamp specially designed for handling heavy metal plates and thelike.

The invention herein described embodies certain improvements over thattype of clamp disclosed in my copending. application filed lin theUnited States Patent Office on November l5, 1943 under SerialNo.510,414.

An object of the invention is to provide a clamp composed of a framehaving opposing pivotally mounted jaws for gripping the plate to belifted with means for temporarily latching one of said jaws in inactiveposition to permit the release of the clamp from the plate when theplate has been landed at its destination.

A further object of the invention is to provide a clamp of the characterdescribed wherein the jaws are normally in active position ready toengage with the plate to be lifted with means for temporarily latchingone of the jaws inactive when the clamp is ready to be disengaged fromthe load.

With the above and other objects in view the invention has particularrelation to certain novel features of construction, operation andarrangement of parts, an example of which is given in this specicationand illustrated in the accompanying drawing, wherein:

Figure 1 shows a sectional View of the clamp taken on the line I -I ofFigure 2.

Figure 2 shows an edge View.

Figure 3 shows a cross sectional view taken on the line 3-3 of Figure 1.

Figure 4 shows a fragmentary sectional view taken on the line I-I ofFigure 2 and showing one of the clamp jaws latched inactive to permitthe release of the clamp from the plate.

Referring now more particularly to the drawing wherein like numerals ofreference designate similar parts in each of the figures the numerals I,I designate side plates of the frame which are anchored together bysuitable cross rods as 2, 2a and 2b which space the side plates apart.

The lower ends of the side plates have the deep slots 3, 3 to receivethe edge of the plate 4 to be lifted. On one side of the slot there is ajaw 5 pivoted on the cross pin 6 and Whose upper end has a transversearcuate slot 6a through which the bolt 2b extends.

The inner margin of this jaw extends into the slots 3 and has a seriesof teeth arranged in r' the same plane.

On the other side of the slots 3 there is a jaw 'I which is pivoted onthe eccentric pin 8 and its operative face is arcuate and'serrated andmay be swung intoy the slots to grip the plate as shown in Figure 1` ormay be retracted as shown in Figure 4. A

There is a control link 9A between the plates. Outwardly of the pivot 8,the jaw 'l is4 slotted and one end of. the link 9is pivoted in this,slot on the pin I0 whichextends through saidja-w-and link. At theopposite side ofl the' frame there are the toggle levers I-I',` I'Iwhich are pivoted, at one end, on the pin I2', connecting said platesand the other ends of which are, providedv with opposing slots as I3. Across bolt i3d extends through said slots and through the other end ofthe link 9,

A clevis I4 embraces the toggle levers and the ends of its side armshave bearings on the bolt I3a, said bolt being retained in position bythe usual head on one end and nut on the other end.

Near its lower end the outer margin of the link S has a notch I5 thereinand there is a latch I6 pivoted between said cross plates on the pinI'I. The latch is normally held disengaged from the notch by means of ayoke I 8, one end of which is pivoted to the upper end of the margin andwhose other end is connected to one end of a pull spring I9. The otherend of this pull spring is attached to an anchor 20 carried by the upperend of the jaw 5.

The latch I6 has a transverse slot 2| through which the bolt 2a extendsand which limits the range of movement of said latch.

In operation the jaw 1 is free to move. A lifting cable is connected tothe clevls I4. The clamp may be applied to the plate 4 which is usually,but not always, in horizontal position and an upward pull on the cablewill cause a corresponding longitudinal movement of the link 9 whichwill swing the jaw 'I into engagement with the plate and the jaw 5,being pivotally mounted, will adjust itself in accordance with theposition of the plate so as to take a rm hold thereof. The plate will bethus securely gripped between the jaws.

When the plate is landed, at destination, and the cable is slacked olf,the link 9 will movedownwardly carrying the notch I5 beneath the activeend 22 of the latch I6 and said latch may then .be forced inwardly intoengagement with the notch to hold the jaw 'I retracted, as shown inFigure 4, so that it will not re-engage the plate when it is desired todisengage the clamp from the plate. Usually this will be doneautomatically for the reason that the plates are usually delivered oneby one to form a stack of plates which extend vertically and as eachplate is landed in position alongside the stack and is leaned againstthe stack, the link 9 will move downwardly and the latch I6 will restagainst the stack and be pressed inwardly until its end 22 engages inthe notch I and upon upward pull of the cable the jaw I will be heldretracted and the clamp will release the plate.

When the plate is released and the clamp is swung into position to beengaged with another plate, the slack on the cable will permit the latchto be disengaged from said notch, by the pull of spring I9 thus leavingthe jaw 'I free to move as before.

As herein above stated the plate to bev lifted will often lie inhorizontal position while the clamp is attached thereto. If the jaw 5 isunderneath the plate when an upward pull is taken on the cable, the boltI3a will move upwardly along the slots I3 causing the toggle levers tomove downwardly until they are stopped by the rod 2 and the bolt I3a-will move on up along the slots I3 thus imparting a tension to the link9 and moving the jaw 1 into engagement with the plate. If the slots werenot provided, no tension should be exerted through the link 9 until theplate had been moved to approximately vertical position and in such casethe clamp might slip-off the plate before the jaw 1 came -into action.

What I claim is:

l. A plate clamp comprising a frame, opposed jaws pivoted on the frame,each of said jaws having a plate-gripping surface, lifting means for theclamp including a link connected to one of the jaws and eiective toactuate said jaw into gripping relation with an object between the jawsupon elevation of the clamp by said means, a latch, means normallyholding the latch inactive, interengaging means carried by the latch andlink, respectively, adapted to be interengaged, upon movement of thelinkfto release its jaw, whereby said jaw will be temporarily retainedin inactive position.

2. A plate clamp comprising a frame having confronting, plate gripping,jaws, one of said jaws being pivoted to move into and out of grippingrelation with an object between the jaws, a link pivoted at one end tothe pivoted jaw, a toggle lever pivoted at one end to the frame andwhose other end is provided with a slot, a cable attaching means movablein said slot and to which the other end of the 1ink is connected, saidlink being connected to the pivoted jaw at a point such that uponelevation of the clamp by the cable the pivoted jaw will be actuatedinto gripping relation with an object between the jaws, a latch,interengaging means carried by the latch and link, respectively, andarranged to be interengaged when said pivoted jaw is moved to inactiveposition to temporarily retain said pivoted jaw in said inactiveposition.

RODNEY S. WALDRUP.

